Library Description Schema

Library description files are XML files that define libraries. Libraries aggregate items from local and remote storage locations into a single view in Windows Explorer. Library description files follow the Library Description schema and are saved as *.library-ms files.

Overview of the Library Description Schema

Libraries contain files that are stored in one or more storage locations. Libraries do not actually store these files; instead, they monitor the folders that contain the files, and let users access and arrange the files in different ways. For example, a user can have music files in multiple folders on a local hard disk and also on an external hard disk. Using the Music Library, the user can access all of those files at the same time and sort them all by artist name or album title as a single group.

The Library Description schema consists of three major parts, described in the following table:

General library information

Information about the library, such as name, owner, version, icon, that Windows Explorer can use when it displays the library to a user.

Library properties

One or more properties that describe the library. These custom properties are specific to the library.

Library locations

One or more search connectors that identify storage locations to include in the library. Each of these locations can also have a unique set of properties.

Library files in Windows 7 are stored in the known folder, FOLDERID_Libraries. By default, the FOLDERID_Libraries folder is located at %USERPROFILE%\AppData\Roaming\Microsoft\Windows\Libraries.

Namespace Versioning

Versions of the Library Description file format (*.library-ms) are tracked by changing the namespace. For Windows 7, the file format has the following default namespace: http://schemas.microsoft.com/windows/2009/library.

Versions of the library contents, however, are tracked by using the <version> element in a specific Library Description file.

Example of a Library Description File

The following is an example of a Library Description file that defines a library for document files.